Laminated glass retention system

ABSTRACT

A laminated glass retention system for securing a laminated glass subassembly within a window sash or frame member or door panel or similar component includes a retention member applied to the laminated glass subassembly. The retention member generally can include a leg portion that engages of the laminated glass subassembly, and can further include a base portion that is coupled to the frame member in which the laminated glass subassembly is seated. The retention member helps retain the insulating glass subassembly within its frame member when subjected to high winds and wind-borne debris.

CROSS REFERENCE TO RELATED APPLICATION

This is a continuation of U.S. patent application Ser. No. 16/450,052,entitled Laminated Glass Retention System filed on Jun. 24, 2019, whichis a continuation of U.S. patent application Ser. No. 16/119,345entitled Laminated Glass Retention System filed on Aug. 31, 2018, whichis a continuation of U.S. patent application Ser. No. 14/854,322entitled Laminated Glass Retention System filed on Sep. 15, 2015, whichis a divisional of U.S. patent application Ser. No. 13/535,545 filedJun. 28, 2012 which is a formalization of previously filed, U.S.Provisional Patent Application Ser. No. 61/526,060, filed Aug. 22, 2011and U.S. Provisional Patent Application Ser. No. 61/503,686, filed Jul.1, 2011, by the inventors named in the present Application. This PatentApplication claims the benefit of the filing date of these citedProvisional Patent Applications according to the statutes and rulesgoverning provisional patent applications, particularly 35 U.S.C. §119(a)(i) and 37 C.F.R. § 1.78(a)(4) and (a)(5). The specification anddrawings of the Provisional Patent Applications referenced above arespecifically incorporated herein by reference as if set forth in theirentirety.

FIELD OF THE INVENTION

The present invention generally relates to a system and method forretaining one or more layers of glass within a frame of a fenestrationunit, and in particular to a system and method for retaining aninsulated glass substantially including a laminated layer of glassproviding protection against wind borne debris within a window or door.

BACKGROUND OF THE INVENTION

Given often harsher environmental conditions encountered in coastalareas, there have been increasingly stringent standards, rules andregulations being passed with regard to fenestration units such aswindows and doors and the ability of such windows and doors to withstandextreme environmental conditions. For example, in many coastal areas,such as in Florida and along the eastern seaboard, hurricanes andtropical storms having gale force winds and the incidence of wind bornedebris are a yearly occurrence and threat. In addition, it is importantfor the glass subassemblies of such coastal impact windows and doors tobe supported and retained within their window sash or frame assembliesor door panel or frame assemblies after impact, and/or after the glasshas been broken to provide blast mitigation protection. Still further,these windows and doors generally must provide enhanced insulationcapabilities when exposed to temperature extremes, especially in summermonths when temperatures in some coastal areas can reach well over 100°F., while in the winter months, temperatures can be well below freezing.

Currently, for the manufacture of coastal impact products, in order toform such products with the desired levels of strength and stability toretain the insulated glass assembly after contact with windborne debris,additional time generally must be spent during the manufacturingprocess. A common method in the industry to achieve this retention is toadd additional glazing material to the gap between the edge of theinsulated glass assembly and the sash or frame to increase the bond areabetween the glass assembly and the sash or frame, in a process commonlyreferred to as back glazing. Such glazing material must be applied allaround the glass edge in a complete and as full an application aspossible. This generally requires significant craftsmanship/skill on thepart of the workers, and considerable additional manufacturing time toensure that the back-glazing is sufficient to meet required missileimpact and pressure cycling (due to windborne debris) test standards forsuch coastal impact products. Additionally, this method requires all thework to be done in-line during the assembly of the sash/frame, causing apotential drop in efficiency and capacity of the manufacturing assemblyline.

Accordingly, it can be seen that a need exists for a system and/orprocess that enables the more efficient manufacture of insulated glassfenestration units having laminated glass structures, which meet orexceed required coastal impact product standards.

SUMMARY OF THE INVENTION

Briefly described, the present invention generally relates to a systemfor the retention of insulating glass subassembly within a window sashor frame assembly or a door panel or frame assembly or other, similarbuilding components, and methods of assembling such reinforced glasssubassemblies in such building components. The system and method of thepresent invention generally includes a retention member that typicallycomprises a lineal member and can include a resilient body formed from aresilient, flexible extruded or synthetic material. Alternatively, theretention member further could include a fibrous reinforcing tape orfabric material. Still further, the retention member can be formed as acomposite material including a series of fibers or other reinforcingtape materials with an adhesive layer being preapplied thereto, or beingpreviously applied to the insulating glass subassembly, with the tape orfibers reinforcing material thereafter being applied over the adhesivelayer so as to secure the retention member to the insulating glasssubassembly. The retention member engages and supports and retains theinsulated glass sub-assembly within the frame of a window sash or frameassembly or door panel and frame assembly to enable transfer of tensileloads from the insulating glass subassembly to the frame upon impact,which provides protection against wind borne debris that meets orexceeds applicable ASTM and TAS large and small impact pressure cyclingstandards for coastal impact products, as well as applicable ASTM, GSA,AAMA and UFC standards for blast migration protection for such products.

In one example embodiment, the retention member can be formed from alineal material applied about a proximal end of an insulating glasssubassembly. The retention member generally will include a body having aleg portion that can be applied along an inside facing surface of theglass subassembly, and a base portion that extends at an angle away fromthe leg portion and along the proximal interior edge of the glasssubassembly. The base portion of the retention member can be adheredalong the interior facing surface and proximal end of a laminated paneassembly of the insulating glass subassembly and attached to an inneredge of an exterior pane of the glass subassembly. In addition, the baseportion of the retention member further can be adhered or otherwiseconnected to a spacer between the exterior pane and the laminated glasspane structure of the glass subassembly to provide additional, expandedsurface area contact between the insulating glass subassembly and theretention member. Still further, it is also possible to use a retentionmember without a leg portion engaging the insulating glass subassemblyand with its base portion adhered and secured to the proximal end of theinsulating glass subassembly and to the frame channel of the window sashor frame assembly or door panel or frame assembly to retain theinsulated glass subassembly within the frame channel.

In one embodiment, the retention member can be applied to the insulatingglass subassembly prior to the insulating glass subassembly beingmounted within a window sash or frame assembly or door panel or frameassembly, or alternatively can be applied after the insulating glasssubassembly has been seated within the window sash or frame assembly ordoor panel frame or assembly. Typically, a heel bead of a sealingadhesive material will be applied along the channel of the frame inwhich the proximal end edge of the exterior pane of the insulating glasssubassembly will be received, and a bed of glazing material furthergenerally will be applied along a lower portion of the frame channel soas to engage and adhere/seal the exterior facing surface of the exteriorpane of the insulating glass subassembly to the frame. When theinsulating glass subassembly is applied to the channel of the framemember of the window sash frame assembly or door panel frame orassembly, the base portion of the retention member also generally willbe received within the heel bead and bed of glazing material. This notonly helps secure the insulating glass subassembly with the framechannel, but also connects the retention member to the window sash orframe assembly or door panel or frame assembly as well.

In an alternative embodiment, the retention member can comprise a hingedmember formed along the frame of the window sash frame or assembly ordoor panel frame or assembly at an interior end of the channel thereof.The hinged retention member can be formed as a part of the frame and canbe folded over into a position so as to engage the interior facingsurface of the laminated pane structure of the insulating glasssubassembly. An adhesive material, including an adhesive bead, tapematerial or other, similar adhesive further can be applied between thesurface of the pivoting retention member and the interior facing surfaceof the laminated pane structure so as to adhere the retention member tothe laminated pane structure of the insulating glass subassembly.

In still a further alternative embodiment of the present invention, theretention member can be used in conjunction with an interior glass stopfor windows or doors, and which is adapted to engage and connect to thewindow sash or frame assembly or door panel or frame assembly. At leastone barbed spline can be formed along a proximal side of the body of theinterior glass stop, and can be inserted into locking engagement with akerf of the interior sash or door panel component. A reinforcing membercan be applied between a lower surface of the interior glass stop andthe interior facing surface of the laminated glass structure of theinsulating glass subassembly to help seat and secure the insulatingglass subassembly between the frame of the window sash or frame assemblyor door panel or frame assembly and the interior glass stop. Theinterior glass stop further can include a downwardly projecting leg, or,alternatively can be formed with a two-piece structure with a separateconnector that attaches to and secures the body to the interior sashcomponent.

In another embodiment, the combination of the retention member andinterior glass stop can be assembled to form a reinforced window sash orframe assembly or door panel or frame assembly, by first applying theretention member to the glass subassembly, and then the interior glassstop can be mounted to the window sash or frame assembly or door panelor frame assembly by placing the body of the interior glass stop overthe interior surface of the glass subassembly and urging the barbedspline thereof into the kerf of the interior sash component, and withthe connector leg projecting into and becoming at least partiallyenveloped by the heel bead of sealant. Once the sealant has cured, theglass stop will be further rigidly tied to the glass subassembly and tothe window sash or frame member or door panel or frame assembly.

Various features, objects and advantages of the present invention willbecome apparent to those skilled in the art upon a reading of thefollowing detailed description, when taken in conjunction with theaccompanying drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an embodiment of an insulated glass fenestration unithaving a laminated glass structure according to the principles of thepresent invention and utilizing a PVC glass retention member.

FIG. 2A is a plan view illustrating the engagement of a frame memberwith a glass stop pre-applied thereto, with the insulated glassassembly.

FIG. 2B is a cross-sectional view, taken along lines 2B-2B of FIG. 2A,of an additional embodiment of the present invention incorporating a VHBtape material combined with a fiberglass cloth for the retention member.

FIG. 2C is a cross-sectional view of the retention member of FIGS.2A-2B.

FIG. 3A illustrates yet another additional embodiment of the presentinvention incorporating the use of a fibrous or reinforced tape materialfor the retention member.

FIG. 3B is a cross-sectional view of the retention member of FIG. 2A.

FIG. 4A is a cross-sectional view of still a further embodiment of thepresent invention incorporating a fibrous or reinforced tape materialfor the retention member.

FIG. 4B is a cross-sectional view of an alternate construction of theembodiment of the present invention as illustrated in FIG. 4A.

FIGS. 5A-5B are cross-sectional views of yet another embodiment of thepresent invention incorporating a flexible hinge component as part ofthe retention member.

FIGS. 6A-6C are schematic illustrations of one embodiment of a processfor applying the retention member to the laminated glass structure priorto assembly of the glass subassembly and sash or frame member.

FIGS. 7A-7D are schematic illustrations of an alternative embodiment ofa process for applying the retention member to the laminated glassstructure after assembly of the glass subassembly and sash or framemember.

FIG. 7E is a plan view illustrating the engagement of a frame memberwith a glass stop pre-applied thereto, with the insulating glasssubassembly.

FIG. 7F is a cross-sectional view, taken along lines 7F-7F of FIG. 7E,illustrating the engagement of a frame member with a glass stoppre-applied thereto, with the insulating glass subassembly.

FIG. 8A is a perspective view illustrating one example method of theapplication of the retention member to a glass subassembly.

FIG. 8B is a perspective illustration of the retention member withperforations of FIG. 8A applied to an insulating glass assembly.

FIGS. 9A-9C illustrate further alternative embodiments of the presentinvention incorporating the retention member with an interior glass stopfor window sash or frame assemblies and/or door panel or frameassemblies.

FIGS. 10A-10C are cross-sectional views illustrating alternativeconfigurations of the present invention incorporating the retentionmember and glass stop of FIGS. 9A-9D.

Those skilled in the art will appreciate the various advantages andbenefits of the various embodiments of the present invention uponreading the following description of the invention and the embodimentsthereof, with reference to the drawing figures. In addition, thoseskilled in the art will understand that, according to common practice,the various features of the drawings discussed below are not necessarilydrawn to scale, and that dimensions of various features and elements ofthe drawings may be expanded or reduced to more clearly illustrate theembodiments of the disclosure.

DESCRIPTION OF THE INVENTION

The present invention generally relates to a system and method forretaining layers of glass, and in particular a laminated layer of glassof a glass subassembly that is designed to provide protection againstwindborne debris in a window, door or other fenestration unit that meetsor exceeds applicable ASTM and TAS large and small missile impact andpressure cycling standards for coastal impact products, as well asapplicable ASTM, GSA, AAMA and UFC standards for blast mitigationprotection. The present invention is designed to enhance the efficiencyand cost effectiveness of the manufacture of such windows, doors orother fenestration units by enabling easier and more efficient assemblyof a coastal impact product that typically will include an insulatingglass subassembly incorporating a laminated glass structure along therearward side thereof. The present invention further can be incorporatedinto any window or door or other fenestration product that is exteriorlyglazed with the laminated glass layers arranged toward an inside portionor region of the window or door, and is illustrated in the attacheddrawings in various example embodiments. It further will be understoodby those skilled in the art that while example window sash or frameassembly or door panel or frame assembly constructions and measurementsor dimensions may be shown in the attached drawings, such constructions,measurements and dimensions are for descriptive and illustrativepurposes only and should not be taken as limiting the scope of thepresent invention.

For illustrative purposes and not limitation, an example of such glasssubassemblies is shown at 13 in the FIGS. 1-2B, 3A, 4A-4B, 5B, 6B-6C,and 7B-10C. As used herein, the term glass subassembly will includetransparent window components such as insulating glazing units,laminated glass panes, and other like fenestration components. Oneexample glass subassembly 13 is an insulating glazing unit comprising afirst, or exterior, pane of glass 27 and a laminated glasspane/structure 12 at a rearward side thereof so as to be facing aninterior side of the window or door and exterior pane 27 facingoutwardly. As shown in FIG. 1, the laminated pane structure 12 caninclude a series of panes 12 a-12 c, and defines a second, or interiorpane of glass 12 a that defines an interior facing or inside surface 11for the glass subassembly, wherein the panes are held together in aparallel spaced apart manner by a peripheral sealing spacer 26 so as todefine a space S between the panes that can contain air or other gas.The insulating glass subassembly will be received within a channel 14 ofthe sash or frame member 16 of a window or a door panel or frame member,and further generally will be adhered thereto with a bed of glazing 31and a heel bead of glazing 25 typically including a silicone glazingmaterial or other, similar material to meet applicable coastal impactproduct regulations and standards, applied within or along the channelas illustrated in FIGS. 1, 2A-2B and 3A.

In one embodiment, the second, or interior, pane is of the well knownshatterproof type comprising a laminate of two glass panes adhered toone another by an intervening layer of polymeric material. Theshatterproof feature of the second pane reduces the likelihood of piecesof glass becoming dangerous projectiles once impacted on the exteriorside by windborne debris. The shatterproof feature of the second panealso reduces the likelihood of piercing or creating a hole through theglass subassembly from wind borne debris impacting the exterior side ofthe subassembly, thus preventing the envelopment of the structure frombecoming pressurized by hurricane force winds.

FIG. 1 portrays an edge portion of a window unit comprising a portion ofglass subassembly 13, a sash or frame member 16, and a glass stop 43.Glass subassembly 13 is adhesively attached and sealed to surface 32 ofsash or frame member 16 by bed glazing adhesive 31. The structuralintegrity of the window unit can be enhanced by back glazing additionalbed glazing material that extends along inner surface 14 a of framechannel 14 so as to provide additional bonding area and to place aportion of the bond in shear loading rather than tensile loading. Thisadditional adhesive is commonly called a heel bead, shown at 25 in theFIGS. In this embodiment, a glass stop 43 also can be attached, bymechanical, adhesive, or other suitable means, to sash or frame member16 to improve the appearance of the window unit, and may also contributeto the structural integrity of the unit.

The choice of adhesive compositions useful for bed glazing 31 and heelbead 25 is not particularly limited, provided the adhesive materialsexhibit adequate adhesion and sealing for the life of the window ordoor. Silicone materials such as silicone RTV (room temperaturevulcanizing) sealants are well known to be useful for attaching andsealing glass members to frames or sashes. Hot melt silicone materialshave also been found useful. Both types of silicone materials areavailable in various grades from Dow Corning Corporation, Midland, Mich.Adhesives and sealants based on polyurethane, polyamide, polyvinylacetate, other known polymers, and copolymers and other combinationsthereof, may also be useful. It will be appreciated that the materialused for the heel bead in a particular window or door application neednot be the same as the material used for the bed glazing in that windowor door. For example, since the heel bead adhesive material and the bedglazing adhesive material typically bond to surfaces having differentsurface adhesion properties, it may be beneficial to choose differentadhesive materials for the heel bead and the bed glazing to optimizebond strength. Additionally, it may be beneficial to choose heel beadmaterials that optimize mechanical integrity, while choosing bed glazingmaterials that optimize sealing between a glass surface and the sash.

As illustrated in FIG. 1, the present invention includes a retentionmember 10 that is adhered to an inside facing surface 11 and edge 15 ofthe laminated pane/structure 12 of the insulated glass sash assembly 13,which itself is received within the channel 14 of the window sash orframe member 16. In alternative embodiments, retention member 10 alsomay be attached to an end edge 27 a of the first or exterior pane 27 ofthe glass subassembly 13. It will be understood that in yet otherembodiments, sash or frame member 16 may instead be a frame of a doorpanel, a fixed window frame, or other structure surrounding andsupporting a glass subassembly. As illustrated in FIG. 1, the retentionmember 10 generally is a lineal member formed with a body 20 having asubstantially L-shaped configuration, including a base portion 21 and alaterally extending projection or leg 22 that extends at approximately a90° angle away from the base portion. Additionally, the retention membercould be formed with a substantially U-shaped construction, extendingaround both facing surfaces 11/27 b of the glass subassembly, as long asit does not interfere with the bed glazing and the engagement/contactbetween the bed glazing and the glass subassembly. As a furtheralternative, the retention member could comprise a unitary memberattached to the proximal edge 15 of the glass subassembly 13, without aleg portion engaging the inside facing surface 11 of laminatedpane/structure 12, and with the base portion of the retention memberextending into and being coupled/secured to the frame channel 14 by thebed glazing 31 and/or heel bead 25.

Retention member 10 further may include other features, such as anadhesive channel or recess 22 a formed along the body 20, which definesa pocket adapted to receive an adhesive material 25 a therein to adherethe body to the glass subassembly. Additionally, ribs 23, or otherengaging features that can increase the area of contact of the retentionmember with the heel bead and/or bed glazing also can be used, which mayimprove the attachment of retention member 10 to heel bead 25 byextending into and engaging the heel bead as shown in FIG. 1 so as tosubstantially secure the retention member into the heel bead andchannel. As shown in FIGS. 7C-7D, such ribs are optional and are notnecessarily required. In alternative embodiments, surface 14 a may alsoinclude ribs serving a similar function. Alternative embodiments inwhich ribs 23 mechanically interlock with corresponding ribs formedalong surface 14 a of the channel 14 are also contemplated.

Retention member 10 may be produced by extrusion of a polymeric materialsuch as polyvinyl chloride (PVC), though other polymeric materials mayalso be suitable. The extruded retention member stock may be cut intoone or more individual sections for each side of glass assembly 13, ormay be provided in longer sections and notched at corner locations topermit bending around corners. In yet other embodiments, retentionmember 10 may be produced as a single component that frames the glasssubassembly 13, by, for example, injection molding, thermoforming, orother processes suitable for the production of framing members.Retention member 10 may be installed on the glass subassembly 13 eitherbefore installation of the glass subassembly 13 onto sash or framemember 16, or after.

As in the case of bed glazing and heel bead adhesives, the choice ofadhesive for attachment of the retention member to the insulating glasssubassembly also is not particularly limited, provided the adhesivebonds with sufficient strength to at least portions of the associatedsurfaces of the insulating glass subassembly and to the retentionmember, and provided that the bonding is long-term, without significantbond deterioration over the life of the window. An adhesive that hasbeen found suitable is VHB transfer adhesive, available from 3M Company,of Maplewood, Minn. The VHB adhesive, which can be laminated to theretention member and is provided with a removable liner to protect theadhesive until the retention member is ready for application to theglazing unit, at which time the liner typically will be removed justprior to application. It also can be useful to apply a primer to theinterior side of the glass subassembly and/or other surfaces to whichthe adhesive materials for attachment of the retention member to theinsulating glass subassembly, prior to application of retention member10 in order to further improve adhesion of retention member 10 to theglass. Suitable primers are available from 3M, as well as from othersources. Suitable methods for applying liquids, in particular theprimer, to solid surfaces in well-defined strips are also well-known,and include the use of sponges, rollers, and combinations thereof, aswell as other like fluid application devices. In other embodiments,retention member 10 may be attached to subassembly 13 by a flowableadhesive such as a silicone material of the type used in bed glazing.

In accordance with the method of the present invention, aftermanufacture of the insulating glass subassembly 13, the retention member10 generally can be adhered to the insulating glass subassembly. Thiscan be done off-line or potentially at an outside vendor who isresponsible for the manufacture of the insulating glass subassembly. Theretention member can be applied using various adhesives or using otherknown methods for bonding the retention member to the outside edge 15,or the outside edge 15 and the interior proximal edge 27 a of theinsulating glass subassembly that is to be received within the channel14 of the sash or frame member 16 or other fenestration frame.

Methods of assembly of a window sash or frame member assembly or doorpanel or frame assembly are illustrated in more detail in FIGS. 6A-6Cand 7A-7F. In the method shown in FIGS. 6A-6C, bed glazing material 31and the heel bead material 25 can be applied to surface 32 prior toplacement of subassembly 13. Subassembly 13, with retention member 10pre-installed thereon, can then be placed onto bed glazing material 31and heel bead material 25 and pressed down against edge 33. Glass stop43 is then installed, using, for example, adhesive or other attachmentmethods known in the art. If necessary, the adhesive materials are thenallowed to cure for a period of time prior to further handling of theassembled unit. Alternative assembly methods, shown in FIGS. 7A-7F,follow the same sequence as that in FIGS. 6A-6C, with the exception thatretention member 10 is not pre-installed on subassembly 13. Rather,subassembly 13 is first installed onto surface 32, using bed glazingmaterial and heel bead material, as before. Retention member 10 can thenbe installed by pressing it into place, so that its lower edge isembedded in heel bead 25. Finally, glass stop 43 is indicated in FIGS.6B-6C and 7B-7F. It will be recognized that this method requires thatretention member 10 be sufficiently rigid to penetrate the heel beadduring installation.

In yet another embodiment, in a process called groove or channelglazing, separate glass stop members can be first attached to theirrespective sash or frame members prior to assembling the sash or framemembers into a complete sash. An example of such a process isillustrated in FIG. 7F and described in U.S. Pat. Nos. 6,167,662,5,622,017, and 4,615,159, which are incorporated by reference as if setforth fully herein. Bed glazing materials and heel bead materials arethen put in place on the appropriate channel surfaces of each of thesash members, after which the sash members can then be slid into placeover the edges of glass subassembly 13, where their ends meet at thecorners to form a complete sash surrounding glass subassembly 13. Itwill be recognized that when this glazing method is used, sash membersand glass stop members need not be separate parts, but can be producedas single units having channels for receiving the edges of the glasssubassembly, thereby further adding to the strength of the assembledunit in resisting impact from wind borne debris. In addition, in such anembodiment, the retention member generally will be pre-applied to theglass subassembly prior to its insertion into the sash assembly.

Referring again to FIG. 1, retention member 10 itself can be formed indifferent sizes, thicknesses and/or lengths, with the base or legportions thereof being of varying lengths depending upon the size andconfiguration of the channel within the window sash or frame member ordoor panel or frame member and/or the profile thereof. For example, inone embodiment indicated in FIG. 1, the base portion can beapproximately 0.795-1.00 inches in length while the leg portion can beapproximately 0.240-0.250 inches. It will be understood, however, thatthe leg and base portions can be of greater or less lengths and can beof varying thicknesses as needed to ensure a matched, engaging fit andseating within the channel 14 without interfering with the proper fit orseating of the insulating glass subassembly within the channel. Portion21 of retention member 10 may extend to corner 27 b of first pane 27,but may also extend for shorter distances or longer distances, providedthat it extends for a sufficient distance into heel bead 25 to provideadequate retention strength, in accordance with applicable large andsmall missile impact and pressure cycling and blast mitigation standardsfor coastal impact products, and without interference with thecontact/engagement between the bed glazing and the glass subassembly,and without requiring additional fasteners to secure the glasssubassembly within the frame channel.

The retention member 10 further can be formed from a variety of natural,metal, composite or synthetic materials, such as a polyvinyl chlorideand glass composites, flexible polyvinyl chloride, polyethylene, nylon,elastomeric materials, or other, similar materials and/or combinationsthereof that have sufficient strength and mechanical propertiesregarding tensile strength and rigidity, and further potentially adesired amount of elongation and/or shock absorption or energydissipation capabilities to transfer tensile loads from impact from theglass subassembly to the frame of the window sash or frame assembly ordoor panel or frame assembly to enable the glass subassembly withstandimpacts, and retain the laminated layer of glass within the channel ofthe window sash or frame member or door panel or frame member bysubstantially supporting and retaining the glass subassembly followingimpact and/or pressure cycling. It may also be useful for retentionmember 10 to exhibit elastic or visco-elastic properties that allow itto undergo elongation or deformation of the retention member followingimpact and/or pressure cycling.

Referring to FIGS. 2A-2C, in another embodiment, retention member 200can be formed from a composite, tape-like stock material 38 having awidth W=X+Y, wherein X is the length of projection 22 and Y is thelength of base portion 21, and comprising a flexible backing covered onone side by a pressure sensitive adhesive. The choice of backingmaterial is not particularly limited, provided that it is sufficientlyflexible to be formed into the shape of retention member 200 and able tostretch while absorbing energy during impact while further exhibitingsufficient tensile strength to withstand the impact and pressure cyclingloads to which it will be subjected. Particularly useful backingmaterials are those containing fiberglass fabric or similar fibrousfabric materials, which may be either woven or non-woven. In addition,various sheet or film materials may also be useful. Other fabrics,either woven or non-woven, may also be useful.

Referring to FIGS. 2B and 2C, the retention member 200 comprisescomposite member 38 that can include a flexible backing 210 (FIG. 2C)with adhesive layer 220 attached thereto. Backing layer 210 may be afabric, such as a fiberglass or a polymeric fabric, either woven ornonwoven. In some embodiments, backing layer 210 may be a fiberglassscreen material. In yet other embodiments, backing layer 210 may be afilm or other flexible sheet material. When backing layer 210 is a filmor sheet material, it can comprise a polymeric material reinforced withfibers or other known reinforcement materials. While it is useful forbacking 210 to be sufficiently flexible to be easily folded into placeduring installation on the glass subassembly, it may also be useful inother embodiments for backing 210 to soften at elevated temperatures, sothat it can be heated and pre-folded prior to installation.

Retention member 200 is adhesively bonded, at a first edge, to insidesurface 11 (FIG. 2B) of laminated panel 12, and bonded at a second edgeto heel bead 25. Bonding of the retention member 200 to heel bead 25 canbe enhanced by embedding a portion of it into heel bead 25, as shown inFIG. 2B. Adhesive layer material, an acrylic, or other similar adhesiveor bonding material 220 (FIG. 2C) may be a pressure sensitive adhesivematerial such as 3M VHB adhesive. This adhesive layer can be of variousthicknesses, varying the thickness of the adhesive layer may providemore flexibility or cushioning, which could increase the time durationof the energy transfer, thus reducing the load transferred, whileexperiencing impact or pressure cycling loads. In some embodiments, afabric backing may be at least partially embedded in the adhesive layer.

The ability of glass subassembly 13 (FIG. 2B) to withstand impactloading can be enhanced by providing a more resilient, that is to saymore robust, coupling between subassembly 13 and sash 16. In someembodiments, it may be useful to increase the flexibility of thiscoupling by reducing the thickness and elastic moduli of backingmaterial 210 used in the retention member. In addition, in someembodiments the strength of the coupling between subassembly 13 and sash16 also may be affected by bonding of retention member 200 to edges 15and/or 27 a of the glass subassembly 13, and possibly to edge 26 a ofthe spacer 26, such as with a layer of an adhesive material. As aresult, resistance to impact or blasts may be enhanced by bondingretention member 200 to one or all of edges 15, 27 a and 26 a, so as toprovide increased surface area control and coupling between theretention member and the components of the glass subassembly, therebyallowing enhanced engagement and/or grip onto subassembly 13 duringimpact or blasts.

In yet another embodiment, illustrated in FIGS. 3A and 3B, retentionmember may comprise a composite structure 300 that can include a backinglayer 310 (FIG. 3B) with adhesive 320 adhesively bonded thereto. Backing310 may comprise a fabric or other fibrous material contained in apolymeric matrix and adhesive layer 320 may be a pressure sensitiveadhesive of the general type conventionally used in pressure sensitiveadhesive tapes. Alternatively, adhesive layer 320 may be a heatactivated adhesive. In yet other embodiments, backing 310 may be afabric, either woven or nonwoven, and adhesive layer 320 may be anadhesive material that at least partially penetrates layer 320 while inaddition providing an adhesive layer. Other backings and adhesive layersthat meet the requirements for a retention member will be apparent toone skilled in the art.

In yet another embodiment, a flexible retention member may be suppliedwithout adhesive, and an adhesive layer may be applied to a suitableedge portion of surface 11 prior to application of the flexibleretention member. Optionally, adhesive may also be applied to edgesurfaces 15 and 27 a prior to application of the flexible retentionmember, and further can be applied to the edge 26 a of spacer 26 tofurther enhance the surface contact and grip of the retention member.The applied adhesive may, in some embodiments, be an adhesive such as 3MVHB transfer adhesive. In other embodiments, the adhesive may be aflowable adhesive such as silicone RTV adhesive, or a heat activatedadhesive such as a hot melt adhesive. Still further, the adhesive usedfor attachment of the retention member could be applied to the glasssubassembly, for example, by skim coating the surfaces of the glasssubassembly with an adhesive, such as a silicone adhesive, andthereafter applying the tape material of the retention member over theadhesive layer to adhere it to the glass subassembly.

Referring to FIG. 4A, in yet another embodiment, retention member cancomprise a reinforcing or fibrous tape material 38, is bonded to insidesurface 11 of subassembly 13 and to sash wall 14 a such as by anadhesive layer 39 a. The retention member 38 may be rigid or flexible.When the retention member is rigid, it can enhance retention ofsubassembly 13 in sash or frame assembly or door panel or frameassemblyl6, in the manner previously described for other embodiments.When the retention member is flexible, it may allow considerablemovement of subassembly 13 relative to sash or frame assembly or doorpanel or frame assembly 16. This may be useful in controlling the mannerin which energy is transferred from the impacting debris to the windowunit by increasing the time duration of the energy transfer, thusreducing the peak load transferred.

In another alternative embodiment, shown in FIG. 4B, surface 14 a of thechannel 14 of the sash or frame assembly or door panel or frame assemblyalso may be oriented at an angle that improves the coupling betweensubassembly 13 and the sash by placing the tape material retentionmember 38 with its base extending along and adhered to the angledsurface 14 a, such as with an adhesive 39 a. Such a mounting arrangementaligns the retention member in a more tensile loading condition duringimpact, and further places the adhesive bond 39 a between the tapematerial retention member 38 and surface 14 a in shear loading conditionrather than in a peeling mode during such impact.

FIGS. 5A and 5B illustrate still a further embodiment of the presentinvention, wherein the retention member 400 is formed as a flexible or“living” hinge. In this embodiment, as illustrated in FIG. 5A, theretention member 400 includes a leg or body portion 40 formed with orattached to the extruded profile of the window sash or frame member 16or door panel or frame member by a flexible hinge 41 formed between theleg 40 of the retention member and the extruded profile of the windowsash or frame member or door panel or frame member, as will beunderstood those skilled in the art. As additionally illustrated in FIG.5A, a tape material 42 generally will be applied to the body 40A in anin-line position. The tape material 42 in this embodiment generally cancomprise a VHB type transfer adhesive or other suitable adhesive-backedtape, and can include adhesive material applied to both sides of thetape. The tape material further generally will be applied to the leg ofthe retention member 40 after extrusion of the window sash or framemember or door panel or frame member profile, and prior to installationof the interior sash component 43 of the window sash or frame member ordoor panel or frame member, in accordance with the various methods ofassembly of a window sash or frame assembly or door panel or frameassembly discussed herein. As FIG. 5B illustrates, the tape material 42will engage the inside surface 11 of the laminated glass pane/structure12 of the insulating glass subassembly 13 when folded over into asubstantially flat lying attitude against the inside surface of thelaminated glass pane/structure. Typically, the leg will be folded overapproximately 90° to provide the desired flat lying, in-line engagementwith the inside surface of the laminated glass pane/structure.

An example of a general application process for applying a retentionmember 10 to an insulating glass subassembly 13, which lends itself toboth manual application and machine application, is shown in FIG. 8A.Referring to FIG. 8A, the retention member 10, such as a fibrous tape,PVC strip or similar material typically having an adhesive materialapplied to an inside surface thereof is first wrapped around and adheredto the edge of the glass subassembly in the manner shown. Positioning ofthe retention member relative to the glass subassembly can be controlledby aligning a bottom edge 45 of the retention member with a bottomsurface 44 of the glass subassembly. While it is convenient to wrap theretention member around the glass subassembly as a single strip, it isalso possible to apply the retention member in sections. For example,separate sections could be applied to each side of the glasssubassembly. Once the retention member has been adhered to the glasssubassembly, notches 46 can be cut in tabs 47, 48, 49 and 50, to producemitered corners when the tabs are folded down, as indicated along lines51, in the directions shown by arrows 52, onto the glass subassembly.Once the tabs are folded down and pressed in place to produce anadhesive bond, the glass subassembly can be handled and moved, for,example, to an assembly station for installation in a window sash orframe assembly or door panel or frame assembly.

It will be recognized that the general process portrayed in FIG. 8Alends itself to many possible variations, including both manual andmachine application. For example, notches 46 could be pre-cut, beforewrapping onto the glass subassembly 13, using suitable methods forproperly locating the notches prior to wrapping. In addition, whileshaping the notches to provide miter cuts generally provides a smoothsurface for the folded over tabs, other notches may be used, where, forexample, overlapping of the folded over tabs, or gaps in the tabs, arepermissible. Additionally, as indicated in FIG. 8B, the retention membermaterial 10 used for wrapping about the glass subassembly could beprovided with a series of perforations, holes, slits or other, similaropenings or passages 54 therethrough, or could be a mesh materialdefining such perforations or passages. The perforations or passages canenable an adhesive material, such as the bed glazing material 31, heelbead 25, or other adhesive material, to flow or pass through theretention member to facilitate engagement and adherence of the adhesiveof the retention member to the glass subassembly and to increase theengagement and encapsulation of the retention member by this adhesivematerial.

Machine wrapping of the retention member 10 onto the edge of insulatingglass subassembly 13 can be done in a variety of known ways. Forexample, tape dispensing heads that carry a roll of the material to bedispensed, remove any protective liner therefrom, position the dispensedmaterial, and press it into place along the edge of insulated glassassembly 13, are well known to those skilled in the art. Positioning andmovement of the dispensing head relative to insulating glass subassembly13 can be done in a variety of ways, some involving movement of thedispensing head relative to insulating glass subassembly 13, and,alternatively, movement of insulating glass subassembly 13 relative tothe dispensing head. Devices such as vacuum chucks for holding theinsulating glass subassembly 13 while wrapping are well known. Likewise,cutting of the tape material of the retention member to free thedispensing head from the insulating glass subassembly 13 once wrappingis complete can be done in a variety of known ways. In addition, it maybe convenient, in some instances, to pre-cut the retention member to asuitable predetermined length prior to wrapping. Folding and pressing oftabs 47-50 can also be done in a variety of known ways, involving, forexample, use of one or more rollers to press the tabs into place, use offlat bending and pressing devices, or combinations thereof.

It also will be appreciated that while the present embodiment has beenapplied to rectangular windows, the same general scheme can also beadapted to apply to other shapes. In addition, while the presentembodiment portrays the retention member as a continuous strip, theremay be instances wherein a series of separate strips may be used. Forexample, windows involving circular or other curved shapes may requirethat the retention member be provided in short strips, or in longerstrips with multiple notches of suitable shape.

Control of the steps in the general process of applying the retentionmember to the insulating glass subassembly 13 may be performed with arange of different levels of mechanization, automation, and integration.For example, the various steps in the process may be performed byseparate powered tools designed specifically for each task butcontrolled manually at each step. Alternatively, the entire process maybe controlled electromechanically, using switches, sensors, and otherelectrical devices to control the entire operation without operatorintervention. Yet another level of control can be achieved by use of adigital system, which would enable the system to utilize input to acomputer.

Coastal impact window products with insulated window subassembliesincluding laminated glass layers formed utilizing the retention methodand member according to the principles of the present invention havebeen found to provide mechanical properties that meet or exceed theglazed opening protection requirements of large and small missile impactand pressure cycling tests as set forth in accordance with ASTM E1886and ASTM E1996 standards, and TAS 201, 202 and 203 (High-VelocityHurricane Zones—Impact Tests for Wind-Borne Debris) buildingrequirements and AAMA 506 standards. In addition, the use of theretention member can assist in providing additional blast mitigationprotections in accordance with ASTMF 1642, GSA T501, AAMA 510, and UFC4-010 standards, and for security applications to aid in the retentionof the laminated glass layer, and the insulating glass subassemblygenerally, within the window sash or frame assembly or door panel orframe assembly after the glass materials have become broken or crackedand/or following impact of debris thereagainst.

Testing on such products was conducted with a sampling of window unitsincluding units described in the above-discussed configurations of thepresent invention. The windows were subjected to the large and smallmissile impact and pressure cycling test requirements as set forth inaccordance with ASTM E1886 and ASTM E1996 standards, and TAS 201, 202and 203 (High-Velocity Hurricane Zones—Impact Tests for Wind-BorneDebris) building requirements and AAMA 506 standards. Test resultsindicated that the use of the retention members described providedenhanced protection against impact and pressure cycling so as to meet orexceed required coastal impact product standards.

Glass stops can also play a role in enhancing the retention of glasssubassemblies in sashes or frames. FIGS. 9A-9D illustrate an alternativeembodiment of the present invention, in which the retention member 10can be used in conjunction with added coupling of interior glass stop 60to a sash or frame. Such an interior glass stop 60 generally cancomprise a vinyl extrusion or similarly formed element 61 that typicallycan be covered with a veneer wrap 62, such as thin wood veneer or othersimilar wrapping. FIGS. 9A-9C illustrate various configurations forcoupling of the interior glass stop 60, with each of the varyingconfigurations generally including a body portion 63 adapted to engageand connect to the interior sash or door panel component 93 for a windowsash or frame assembly or door panel or frame assembly. At least onebarbed spline 64-74 generally will be formed along a proximal side ofthe body of the interior glass stop, and, as illustrated in thedrawings, generally can be rolled or otherwise inserted into lockingengagement with a kerf 66 of the interior sash or door panel component93.

As shown in FIGS. 9A-9C, the reinforcing member 90 can be adhered to theinterior surface 11 of the laminated glass structure of the insulatingglass subassembly 13, and, optionally, to edge 15 of second pane 12 b,as in the previously disclosed embodiments. Also as in previousembodiments, member 90 extends into heel bead 25. While any of thepreviously disclosed retention members may be used in this embodiment, aparticularly useful retention member can include a double-sided tapeincluding a substrate material such as a reinforced fiber, woven ornon-woven cloth material or reinforcing tape material having an adhesivematerial applied to both sides. For example, the retention member couldinclude a VHB transfer adhesive or equivalent alternative adhesivematerial such as supplied by 3M Corporation. As in previously disclosedembodiments, the retention member 90 helps anchor the insulating glasssubassembly to the window sash or frame member or door panel or framemember by being embedded in and adhesively bonding to heel bead 25.

Looking at FIG. 9A, which illustrates in more detail a first embodimentof the combined retention member 10 and interior glass stop 60, in whichthe retention member is applied between the interior surface 11 of theinsulating glass subassembly and lower surface 67 of the body of theinterior glass stop. In this embodiment, glass stop 60 further includesbarbed spline 64 that tightly engages kerf 66 in door panel or framecomponent 93 to further retain both glass stop 60 as well as glazingunit 13. Such an embodiment can be used in conventional window or doorapplications to provide an enhanced interior glass stop for the glasssubassembly. Additional embodiments of the interior glass stop 60′ and60″ are further illustrated in FIGS. 9B and 9C, and can have particularapplication for use in coastal impact products, due to the additionalcoupling to heel bead 25. In the embodiment shown in FIG. 9B, theextruded body of the interior glass stop 60′ further includes leg 68that extends downwardly from the lower surface 67 of the body 63, alongthe channel 14 and generally terminates in a hooked lower end 69, whichis embedded in heel bead 25.

Alternatively, as indicated in FIG. 9C, the interior glass stop 60″ canbe formed with a two-piece structure, including a substantially solidbody 63″, and a separate connector 70 that attaches thereto and includesa projecting portion 69 that extends into heel bead 25, and that furtherincludes barbed spline 64 that secures the body to door panel or framecomponent 93. The connector 70 can be extruded, stamped or otherwiseformed from various materials, including metal, composite, or syntheticmaterials, and generally will include a horizontally extending base 71,with the first upstanding barbed spline 72 that engages a kerf 73 formedin the body 63″. A second, downwardly extending barbed spline 74 engagesthe kerf 66 formed in the interior sash component, and further includesan upwardly projecting leg 75 having an inwardly directed hookprojection, indicated at 76, that engages a slot or kerf 77 formed alonga rearward side of the body 63″ of the interior glass stop to helpfurther secure and connect the connector 70 to the body of the interiorglass stop 60″. In addition, leg 78 extends downwardly from the base 71and terminates in a substantially hooked or barbed lower end 79, whichis embedded in heel bead 25.

The combination of the retention member 10 and interior glass stop 60′can be assembled to form a window sash or frame assembly or door panelor frame assembly, generally by first applying the retention member,such as using one of the methodologies as discussed above, for examplefollowing the process steps as outlined in FIGS. 6A and/or 6B.Thereafter, the interior glass stop can be mounted to the window sash orframe assembly or door panel or frame assembly by placing the body ofthe interior glass stop over the interior surface of the glasssubassembly and urging the barbed spline thereof into the kerf of theinterior sash component. As further indicated in the embodiment shown inFIG. 9B, the leg of the interior glass stop likewise will be urgeddownwardly, through the channel 14 between the glass edge and theinterior sash component and/or sash or frame member 16 or door panel orframe member, with the leg projecting into and becoming at leastpartially enveloped by the heel bead 25 of silicone sealant. Once thesealant has cured, the glass stop will be further rigidly tied to theglass subassembly and to the window sash or frame member 16 and/orinterior sash component. The further inclusion of the additional legwith such an interior glass stop profile can additionally help reduce orpossibly eliminate the requirement for backfilling the entire cavitybetween the glass edge and interior sash component and can furtherprovide an additional benefit of performing the function of glassspacers or setting blocks.

In yet other embodiments, such as shown in FIGS. 10A-10C a glass stopthat is sufficiently strongly coupled to the frame or sash may providesufficient retention of the glass subassembly in the frame or sash,without the need for additional retention members. FIGS. 10A and 10Billustrate alternative constructions of the embodiment of the presentinvention illustrated in FIGS. 10A-10C, wherein an adhesive member 10′is used in conjunction with varying configurations of an interior glassstop 60-60′ for windows or patio doors. For example, FIG. 9A illustratesthe use of adhesive member 10′ with the interior glass stop 60illustrated in FIG. 9A as including an extruded body 63, veneer wrap 62and a barbed spline 64 engaging the interior sash component. FIG. 10Billustrates the use of the shortened retention member 10′ with theconstruction of the interior glass stop 60′ as shown in FIG. 9B,including an additional downwardly projecting leg 68. In theconstructions illustrated in FIGS. 10A-10C, the adhesive member 10′generally can comprise a tape material, such as a VHB tape or similaradhesive-backed tape material. The adhesive member in this embodimentfurther generally will be of a reduced length so as to extend only alonga portion of the inside surface 11 of the insulating glass subassembly13, shown as being located between the inside surface 11 of theinsulating glass subassembly 13 and the lower surface 67 of the body 61of the interior glass stop 60-60′.

As therefore indicated in FIGS. 10A-10C, the tape material of theadhesive member will not extend about the corner and outside edge 15 ofthe insulating glass subassembly. Thus, the amount of tape materialutilized for the shortened retention member 10′ can be reduced whilestill facilitating the secure seating and mounting of the insulatingglass subassembly between the interior glass stop and the window sash orframe member or door panel or frame member, without necessarilyrequiring the use of additional exposed fasteners such as nails orstaples; and which generally meets large and small missile impact andpressure cycling test requirements for coastal impact products, as wellas providing enhanced security and resistance to blast migration of thelaminated glass structure of the insulating glass subassembly followingimpact and/or cracking or breaking of such glass materials.

The foregoing description generally illustrates and describes variousembodiments of the present invention. It will, however, be understood bythose skilled in the art that various changes and modifications can bemade to the above-discussed construction of the present inventionwithout departing from the spirit and scope of the invention asdisclosed herein, and that it is intended that all matter contained inthe above description or shown in the accompanying drawings shall beinterpreted as being illustrative, and not to be taken in a limitingsense. Furthermore, the scope of the present disclosure shall beconstrued to cover various modifications, combinations, additions,alterations, etc., above and to the above-described embodiments, whichshall be considered to be within the scope of the present invention.Accordingly, various features and characteristics of the presentinvention as discussed herein may be selectively interchanged andapplied to other illustrated and non-illustrated embodiments of theinvention, and numerous variations, modifications, and additions furthercan be made thereto without departing from the spirit and scope of thepresent invention as set forth in the appended claims.

The invention claimed is:
 1. A window or door assembly comprising: aglass subassembly with edges surrounded and supported by a frame; theframe and the glass subassembly each having an inside surface that facesthe inside of a structure when the window or door assembly is installedand an outside surface that faces the outside of the structure when thewindow or door is installed; the frame having a generally L-shapedinterior channel defined by a peripheral wall extending from the insidesurface of the frame to a corner edge and an inside facing attachmentsurface extending from the corner edge of the peripheral wall to a freeedge; the edges of the glass subassembly being seated within thegenerally L-shaped interior channel with a space defined between theedges of the glass subassembly and the peripheral wall of the channel; aretention member having a first portion that extends along the edges ofthe glass subassembly and engages the inside surface of the glasssubassembly and a second portion that extends along and engages theframe adjacent the L-shaped channel; a leg extending from the retentionmember into the space between the edges of the glass subassembly and theperipheral wall of the channel, the leg extending to a distal edgespaced from the inside facing attachment surface of the L-shapedinterior channel and being spaced from the edges of the glasssubassembly and from the peripheral wall of the L-shaped channel; and abonding material disposed at least in the space between the edges of theglass subassembly and the peripheral wall of the channel with thebonding material at least partially encapsulating the leg; the at leastpartially encapsulated leg securing the retention member to the frame toimprove the resistance of the glass unit to being dislodged from thechannel by an outside force.
 2. A window or door assembly as claimed inclaim 1 further comprising a barbed spline projecting from the retentionmember, the barbed spline extending into and being lodged within acooperating kerf in the frame.
 3. A window or door assembly as claimedin claim 2 wherein the kerf surrounds the L-shaped channel.
 4. A windowor door assembly as claimed in claim 1 wherein the retention membercomprises a glass stop.
 5. A window or door assembly as claimed in claim1 wherein the bonding material comprises a heel bead material.
 6. Awindow or door assembly as claimed in claim 1 further comprising a beadof bonding material disposed between the attachment surface of theL-shaped channel and the outside surface of the glass subassemblyadjacent the edges of the glass subassembly.
 7. A window or doorassembly as claimed in claim 6 wherein the bonding material in the spacebetween the edges of the glass subassembly and the peripheral wall ofthe L-shaped channel is a heal bead.
 8. A window or door assembly asclaimed in claim 7 wherein the bonding material between the attachmentsurface and the glass subassembly comprises a glazing bead.
 9. A windowor door assembly as claimed in claim 8 wherein the heel bead and theglazing bead comprise the same material.
 10. A window or door assemblyas claimed in claim 1 wherein the distal edge of the leg is formed witha hook that is embedded in the bonding material.
 11. A window or doorassembly as claimed in claim 1 wherein the retention member and the legare unitarily formed.
 12. A window or door assembly as claimed in claim1 wherein the retention member and the leg are separate componentssecured together.
 13. A window or door assembly as claimed in claim 12wherein the retention member and the leg are secured with a barbedspline engaged within a kerf.
 14. A window or door assembly as claimedin claim 13 wherein the kerf is formed in the retention member.
 15. Awindow or door assembly as claimed in claim 1 further comprising anL-shaped bracket extending around the edges of the glass subassembly,the L-shaped bracket having a first leg juxtaposed the edges of theglass subassembly and a second leg engaging the inside face of the glasssubassembly.
 16. A window or door assembly as claimed in claim 15wherein at least a portion of the first leg of the L-shaped bracket isembedded within the bonding material in the space between the edges ofthe glass subassembly and the peripheral wall of the channel to enhancefurther the resistance of the glass subassembly from being dislodgedfrom the frame.
 17. A window or door assembly as claimed in claim 1wherein the retention member comprises a glass stop and the leg dependsfrom a connector that is secured to the glass stop.
 18. A window or doorassembly as claimed in claim 17 wherein the connector is mechanicallysecured to the glass stop.
 19. A window or door assembly as claimed inclaim 1 wherein the retention member comprises a glass stop and the legis part of an L-shaped profile having a second leg that engages theinside surface of the glass subassembly beneath the retention member.